Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
hieu van » hieu va, thien van, lieu va
va thanh » gia thanh, ban thanh, le thanh
va tinh » may tinh
nam xuc » cam xuc, nam xua, nam thuc
sach ty » sach y, sach tu, sach thu
da cau » dat cau, va cau
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su ((cac ky) or (sach ty)) nang x hoi. hieu van nam xuc ((va thanh) OR (va tinh)) da cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((cac ky) OR (sach ty)) nang x hoi. hieu van nam xuc ((va thanh) OR (va tinh)) da cau tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((cac ky) or (sach ty)) nang x hoi. hieu van nam xuc ((va thanh) OR (va tinh)) da cau tren".
• Adding a wildcard symbol may retrieve word variants: su ((cac ky) or (sach ty)) nang x hoi. hieu van nam xuc ((va thanh) OR (va tinh)) da cau tren*.